This invention relates in general to an attachment for a foundation frame for pouring a concrete foundation, and particularly to a plate that locates at corners to reduce a tendency for corner cracking.
Many residential homes being built currently have concrete slab foundations, a wooden frame, and a masonry veneer, such as brick. Vertical sideboards are set up at the periphery of the foundation. Spacer boards extend from the upper edges of the vertical sideboards inward. While pouring the foundation, concrete will be poured within the frame flush with the spacer boards and the upper edges of the sideboards. After the concrete has set sufficiently, the sideboards and spacer boards are pulled away from the foundation. Removing the spacer boards leaves a ledge at the edge of the foundation for receiving the base of the masonry veneer.
The wooden frame of the house will be built on the foundation starting just inward of the ledge created by the spacer boards. To install the brick veneer, a mason will build a veneer wall from the ledge upward. It is a good practice to place a plastic film over the ledge to prevent bonding of the mortar to the ledge. The mason will tie the veneer wall to the wooden frame in a conventional manner.
After construction, the foundation will expand and contract due to temperature changes. The foundation may also move due to swelling of the soil, particularly if clay is present. The expansion and contraction of a brick veneer wall is not the same as that of the foundation because of different coefficients of expansion. If the mortar has been allowed to bond to the ledge, substantial pressures will be created, particularly at the corners. This results in cracking at the corners. A cracked foundation corner is unsightly and expensive to repair.
In this invention, a plate is positioned at each of the corners of the foundation frame. The plate has first and second legs, each leg being of substantially the same width as one of the spacer boards. The plate is fastened to a lower side of two of the spacer boards at the corner.
After the concrete has been poured and set, the operator removes the spacer boards and sideboards in a conventional manner. However, the operator leaves the plate in place it at the corner, flush with the ledge. The plate has an upper surface that is formed of a material that will not bond to the mortar. Consequently, bonding of the mortar of the veneer wall to the foundation does not occur at the corner. This reduces the tendency for the corners to crack.